孔目湖闸左岸土工格栅抛投后迎水面最大沉降

根据对(dui)传统(tong)草土(tu)埽(sao)进占(zhan)丁坝(ba)(ba)控(kong)导工程长(zhang)期运(yun)行过程的(de)(de)监测(ce)发现，坝(ba)(ba)顶存在不同程度(du)沉(chen)(chen)降，坝(ba)(ba)头沉(chen)(chen)降最大(da)达(da)到1m，究其原(yuan)因(yin)看(kan)出，传统(tong)草土(tu)埽(sao)进占(zhan)情况下(xia)，埽(sao)体结构长(zhang)期位于水下(xia)，受到河水浸(jin)泡腐蚀的(de)(de)可能性非常大(da)，进而引发坝(ba)(ba)体不均匀沉(chen)(chen)降，且临近水面(mian)的(de)(de)坝(ba)(ba)头沉(chen)(chen)降明显大(da)于坝(ba)(ba)体中部(bu)；甚至(zhi)部(bu)分草土(tu)埽(sao)坝(ba)(ba)已经(jing)出现滑(hua)塌(ta)和严(yan)重变形(xing)，不利于堤坝(ba)(ba)安全。

在土工格(ge)(ge)(ge)栅(zha)进占坝垛(duo)施(shi)工后(hou)按(an)照4m间(jian)距以及(ji)基于坝岸着溜冲刷机理、反映坝体变化(hua)的原则从(cong)连(lian)接处开始共布设20个监测断(duan)面(mian)(mian)(mian)(mian)。其中1#~7#断(duan)面(mian)(mian)(mian)(mian)位(wei)于10#格(ge)(ge)(ge)栅(zha)背水(shui)(shui)面(mian)(mian)(mian)(mian)，8#~13#断(duan)面(mian)(mian)(mian)(mian)位(wei)于10#格(ge)(ge)(ge)栅(zha)迎水(shui)(shui)面(mian)(mian)(mian)(mian)，14#~16#断(duan)面(mian)(mian)(mian)(mian)位(wei)于丁联坝，17#~18#断(duan)面(mian)(mian)(mian)(mian)位(wei)于9#格(ge)(ge)(ge)栅(zha)背水(shui)(shui)面(mian)(mian)(mian)(mian)，19#~20#断(duan)面(mian)(mian)(mian)(mian)位(wei)于9#格(ge)(ge)(ge)栅(zha)迎水(shui)(shui)面(mian)(mian)(mian)(mian)。各监测断(duan)面(mian)(mian)(mian)(mian)沉(chen)(chen)降(jiang)(jiang)变形结(jie)果汇总至表(biao)2。根(gen)据表(biao)中统计结(jie)果可以看出，孔目湖闸左岸填土中土工格(ge)(ge)(ge)栅(zha)抛(pao)投后(hou)迎水(shui)(shui)面(mian)(mian)(mian)(mian)最(zui)大(da)沉(chen)(chen)降(jiang)(jiang)出现在10#格(ge)(ge)(ge)栅(zha)背水(shui)(shui)面(mian)(mian)(mian)(mian)，最(zui)大(da)沉(chen)(chen)降(jiang)(jiang)量为(wei)25.40mm；最(zui)小沉(chen)(chen)降(jiang)(jiang)位(wei)于10#格(ge)(ge)(ge)栅(zha)迎水(shui)(shui)面(mian)(mian)(mian)(mian)，沉(chen)(chen)降(jiang)(jiang)量为(wei)3.70mm；沉(chen)(chen)降(jiang)(jiang)状况明显比传统草土埽进占小，加固效(xiao)果较好。